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I am trying to see if anyone can help me identify a component on a PCB. This device took a voltage spike on its AC line from a lightning strike on our home, and the unit is no longer working.

The component is labeled "SA1" on the PCB, but as you can see, only half of the device remains so I can't get enough unique numbers to cross reference anywhere. This board is immediately down-stream from the power on/off switch, and if I am following the traces on the PCB correctly, this component is soldered between the neutral and ground planes; the hot side of the 120vAC feed is fused with a 5A-250V fuse.

The failed component almost looks like it was a halogen style bulb, but not sure why there would be one in this location on the system, or how it would work with placement between ground and neutral, unless the yellow wire is actually the hot and black is neutral which seems counter to typical color coding practice.

The PCB is labeled with "E154554" & "SH-A 94V-0", but searches for that show many different PCBs with none looking anything like this board. I even saw those same numbers on other boards in this device, so that was rather weird and explains why I am not finding anything in my searches.

If you have any guidance, I would really appreciate it. Just trying to see if replacing this part will fix the issue, or if the spike was such that it has fried things all over inside this unit.

Unidentified Component

PCB

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  • \$\begingroup\$ 94V-0 is a UL flame rating. Many / most PCBs will have that marking as part of their certification. \$\endgroup\$ – Dwayne Reid Nov 24 '19 at 1:25
  • \$\begingroup\$ If the component is between the Earth line and Neutral, the unit should work correctly with that component missing. Use a multimeter to verify continuity between each of the component terminals and the incoming power connections. \$\endgroup\$ – Dwayne Reid Nov 24 '19 at 1:28
  • \$\begingroup\$ Thanks Dwayne. That explains the wide return of stuff when I searched for it. I will keep digging to see if I can find anything. Have ag great evening! \$\endgroup\$ – Joe M Nov 24 '19 at 1:29
  • \$\begingroup\$ Confirmed yellow is earth, white is neutral and black is hot. I agree that it should work, and is making me think that whatever got blown out is further down into the device. I will keep searching, and will also see if I can contact the manufacturer and see if there is a full board replacement that is not too costly to give a try. Thanks \$\endgroup\$ – Joe M Nov 24 '19 at 1:42
  • \$\begingroup\$ The purpose of this board is just a surge arrestor and line filter. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Nov 24 '19 at 2:57
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Probably a gas discharge tube. SA would be "Surge Arrestor". Most of them that we see in the West are ceramic types which would have less tendency to explode, but the glass ones are not unheard of, for example the Okaya products.

You can try to substitute a ceramic type from a source local to wherever you are.

As others have said, the markings on the PCB are a flame rating and probably a UL file number, from which you could find a manufacturer (just of the laminate though, which is completely useless for your purposes- it's made by KUNSHAN SUHANG CIRCUIT BOARD CO LTD in Jiangsu, China).

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  • \$\begingroup\$ This board is from a Japanese massage chair manufacturer Inada. Would this surge arrestor cause the power supply to not function? With it between neutral and ground, it seems like it could be removed and would only then affect the ability to stop a surge... I am a novice at this, so I may be all wet in my thinking... Thanks Spehro!! \$\endgroup\$ – Joe M Nov 24 '19 at 1:46
  • \$\begingroup\$ Yes, unless it vaporized a trace or whatever in its absorbing the last surge. Of course the next surge will probably kill something more vital if you don't replace it with something equivalent or better. \$\endgroup\$ – Spehro Pefhany Nov 24 '19 at 1:48
  • \$\begingroup\$ Yes, it has definitely done something else, as the unit is dead. No reaction when power is switched on. Just need to start tracing into the board and see if I can locate where things go south. All of the destinations for this board's output have more of the brains of the chair, so I am probably going to be out of luck if that is the case. \$\endgroup\$ – Joe M Nov 24 '19 at 1:57
  • \$\begingroup\$ Nah, it probably blew the fuse (which it looks like you've removed) and may have blown a trace off the board. You can easily jump the blown trace with a bit of wire. No problem, easily fixed. \$\endgroup\$ – Spehro Pefhany Nov 24 '19 at 2:01
  • \$\begingroup\$ Yes, the fuse is testing good. And the traces on this board are not delicate and I see nothing jumping out at me. Just have to keep searching. Think good thoughts for me...!! Thanks so much for your help!! \$\endgroup\$ – Joe M Nov 24 '19 at 2:05

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